Meeting Abstract

Publication year: 2007

Pages: H11C-0662-

Journal: Eos, Transactions American Geophysical Union

Volume number: 88

Issue number: 52, Suppl.

Publisher: Wiley

Abstract: 

The ability of a model to capture dominant ecological and hydrological processes is a prerequisite for the use of the model in studying impacts of landuse change on the water balance and nutrient fluxes from a watershed. However, in many cases, available model structures do not adequately represent processes of interest. In these cases, a pragmatic response is to revise the structure to better represent key processes. In this paper we outline a model application strategy designed to inject additional realism into a commonly applied model structure. Here we focus on the SWAT model in an application to the mesoscale (514 km ²) Wetter catchment, in central Germany. The catchment is characterized by a heterogeneous landscape structure and characteristics. The southwestern part is formed by a low mountain range with shallow soils over bedrock and steep slopes. Here lateral subsurface stormflow appears to be the dominant runoff generation process. The central and north- eastern regions of the basin are characterized by deep loess born soils and shallow slopes. We hypothesize that the much larger storage potential of the soils promotes vertical infiltration and storage, and that lateral runoff is much less significant. We utilize a variety of SWAT versions to evaluate the potential effects of this hypothesis on the capacity of the model to capture the measured runoff response. Our results indicate that the original SWAT- structure as well as the SWAT-G structure (which was applied to other low mountain catchments in Germany) are not able to acceptably represent the hydrograph. However, a hybrid of the two structures, specifically designed to reflect differences between the mountainous regions and the more gentle topography does result in a satisfactory representation of the hydrograph. The inclusion of elements from of both model structures (original SWAT and SWAT-G) seems to be the best way to reflect our hydrological process understanding, producing results which capture both the runoff response and the spatial variation in the mechanisms responsible for it.

Harvard Citation style: Julich, S., Breuer, L., Vache, K. and Frede, H. (2007) Evaluation of Distributed Model Structures in Catchment Scale Modeling to Capture Heterogeneous Landscape Characteristics, Eos, Transactions American Geophysical Union, 88(52, Suppl.), p. H11C-0662

APA Citation style: Julich, S., Breuer, L., Vache, K., & Frede, H. (2007). Evaluation of Distributed Model Structures in Catchment Scale Modeling to Capture Heterogeneous Landscape Characteristics. Eos, Transactions American Geophysical Union. 88(52, Suppl.), H11C-0662.